I have the same issue. Running keycloak in docker/kubernetes/aws infrastructure. I have added my theme to the themes directory and tried setting environment variables but still having issues getting my custom theme to be the default for a specific realm when the container restarts. The theme is still there when I restart but I have to reselect it in the dropdown menu for the client. How do I set that to default on container rebuild? Is there a way to edit a standalone.xml file or set an environment variable? The documentation doesn’t seem to cover this scenario.